WOLF-RAYET STARS AND O-STAR RUNAWAYS WITH HIPPARCOS - II - PHOTOMETRY

Abundant HIPPARCOS photometry over 3 years of 141 O and Wolf-Rayet sta rs, including 8 massive X-ray binaries, provides a magnificent variety of light curves at the sigma similar to 1-5% level. Among the most in teresting results, we mention: optical outbursts in HD 102567 (MXRB), coinciding with periastron passages; drastic changes in the light curv e shape of HD 153919 (MXRB); previously unknown long-term variability of HD 39680 (O6V:[n]pe vat) and WR 46 (WN3p); unusual flaring of HDE 3 08399 (O9V); ellipsoidal variations of HD 64315, HD 115071 and HD 1606 41; rotationally modulated variations in HD 6681 1=zeta Pup (O4Inf) an d HD 210839=lambda Cep(O6I(n)fp); dust formation episode in WR 121 (WC 9). In a statistical sense, the incidence of variability is slightly h igher among the WR stars, which might be explained by the higher perce ntage of known binary systems. Among the presumably single WR stars, t he candidate runaways appear to be more variable then the rest.